The Genetics Core facility is one of the research cores in the Rheumatic Diseases Core Center (RDCC) at Washington University. It proposes the following Specific Aims to sustain and develop new state-of-the-art protein services to RDCC members: 1) Support continued progress and growth of the Transgenic and Knockout Mouse Facility;2) Support continued progress and growth of the mouse Speed Congenics Facility;and 3) Support development and use of a new Human Genomics and Bioinformatics Facility. The Transgenic and Knockout Mouse Facility helps RDCC investigators produce new strains of mice by microinjection of transgenic constructs or embryonic stem cells. The Speed Congenics Facility provides custom genotyping to speed backcrossing of mice with defined alleles onto homogeneous genetic backgrounds. The new Human Genomics and Bioinformatics Facility will provide expertise in design and interpretation of high throughput genetics information. All units are devoted to testing new techniques in order to provide the RDCC community with new tools.